C. L. Bush

Lawrence Sheridan and Francis Hudley are now engaged, and he becomes more determined to find out the cause of the fire at his family's estate.
Meanwhile malicious rumours are started by his stepmother and half-brother about Lawrence's behaviour.
Not a stand-alone tale but part of a three part story.

The conclusion to the trilogy - with Lawrence returning to London with some of the answers he needs.
But his stepmother and half-brother are not finished yet. Can they stop the wedding of Lawrence and Francis, and will he find all the answers.

Continuing the story of Laurie and Franny Sheridan but this first in a trilogy concentrates on Lucy Livingston and her relationship with ex-soldier Simon Tucker, who has come to work for the Sheridans.
Unfortunately the mystery didn't come until the end, which left us with a cliff-hanger in this shortish novella.